2009-01-01

MER Glossary

MER Glossary

APXS: Alpha Particle X-ray Spectrometer. One of the four instruments on the rover's arm, it's a chemical sensor. It's less sensitive to iron than the MB, but is better at non-iron chemistry, so the two instruments complement each other.

ATLO: Assembly, Test, and Launch Operations. Pretty much what it sounds like: putting the pieces of the spacecraft together, making sure they work, and lifting them into the sky.

CAM: Command Approval Meeting. This pretty much wraps up the day and is our last chance to review all the sequences and catch any mistakes.

CCT: Compositional Calibration Target. Mounted on the rover itself, just above the arm, it's a plate with a known chemical composition; it can be used to calibrate the APXS and MB.

CMSA: Cruise Mission Support Area. This is where we commanded the rovers when they were on their way from Earth to Mars.

DTE: Direct-To-Earth -- a data pass where we send data directly to listening radio antennae on Earth, not indirectly through an orbiter.

EDL: Entry, Descent, and Landing -- everything from the top of the atmosphere to a safe landing on the surface.

FHAZ: Front HAZCAMs -- the HAZCAMs mounted on front of the rover.

FSW: Flight Software, the software that runs on board the rovers themselves. (As distinct from "ground software," software we run here on Earth.)

Gusev Crater: The 160-km-wide (hundred-mile-wide) crater Spirit landed in. Gusev Crater looks, from orbit, like a Mickey Mouse-head balloon -- the "string" of the balloon is, we think, the bed of the river that fed a lake in Gusev Crater, eons ago.

HAZCAM: Hazard-Avoidance Cameras. These are the camera-pairs mounted just above the rovers' front and rear wheels, on the WEB. They give you a squatting-down, rover's-eye view of the area immediately in front of and behind the rover.

HGA: High-Gain Antenna. It's the one that looks like a lollipop.

HAFIQ: The Hazard-Avoidance Fault Image Queue is the last several images taken by the hazard-avoidance (a.k.a. "autonav") code. If the rover decides to stop, it can be handy to see what led up to its decision; the images in this queue show you that.

IDD: Instrument Deployment Device, the official name for the robotic arm.

ISIL: In-Situ Instrument Laboratory, the official name for our testbed facility.

IST: Integrated Sequencing Team -- more or less, the folks whose job is to get commands up to the rover each day. Roughly equivalent to "uplink team."

LST: Local Solar Time. Roughly, it works like this. Wherever you are on Mars, call it noon (12:00) when the sun is directly overhead (more precisely, when the sun is at its zenith). Then divide the time between that moment and the next noon into 24 periods you call hours, and divide each of those hours into 60 minutes, and so on. They'll be longer than the corresponding Earth time periods because the Martian day is longer, but it's a convenient way to think about time on Mars despite that.

LTP: Long-Term Planning. The LTP team's job is to look beyond today and make sure we're on track to meet the mission's science objectives.

MB: Moessbauer Spectrometer. One of the four instruments on the rover's arm, it's particularly sensitive to iron.

MER: Mars Exploration Rovers. Of course.

Meridiani Planum: Opportunity's landing site. It's pretty much the flattest, smoothest, and therefore safest places we could have landed a rover. Up close, it's like a parking lot, though it proved (much later) to have speed bumps.

MI: Microscopic Imager. One of the four instruments on the rover's arm, it's essentially a digital camera with a microscope lens.

MIPL: The Multimission Image Processing Lab. Among other things, MIPL converts our downlinked images into terrain meshes, the 3-D worlds within which we plan our drives.

MTES/Mini-TES: Miniature Thermal Emission Spectrometer. It's a remote-sensing instrument that reads the heat coming off of stuff and tells us what the stuff is made of.

NAVCAM/NCAM: Navigation Camera. It's one of the camera-pairs on the rover's camera mast. It takes only black-and-white images, but has a wider field of view than the PANCAMs.

PANCAM/PCAM: Panoramic Camera. It's one of the camera-pairs on the rover's camera mast. All of the color pictures from Spirit and Opportunity come from the PANCAM.

PMA: PANCAM Mast Assembly. It's the rover's "neck and head" -- the camera mast that sticks up and has the PANCAMs, NAVCAMs, and MTES on top. (Strictly speaking, the MTES itself is inside the WEB, but the MTES is hooked to a sort of periscope that runs up the PMA.)

PUL: Payload Uplink Lead. The PUL for a particular instrument is the person responsible for commanding that instrument on a particular day.

RAT: Rock Abrasion Tool. One of the four instruments on the robotic arm, it can brush soil off of rocks or drill holes into them. It's my favorite instrument on the rovers, because it lets me make a mark on Mars that will be there for a million years.

RHAZ: Rear HAZCAMs -- the HAZCAMs mounted on the back of the rover.

RoSE: The Rover Sequence Editor, the software I wrote for MER. Part of the RSVP suite, it's the software MER uses to write all commands for the rovers.

RP: Rover Planner, the official name of the rover driver job. They called it that so that not everyone on Lab would know what it meant and try to get the job. I think I'm kidding about that, but I'm not sure.

RP-1, RP-2: Our planning days went through the entire Martian night -- starting in the late Martian afternoon, actually -- too long for a single person to work productively the whole time. So most positions were split into two parts -- 10-hour shifts, with a handover from the first person (the RP-1) to the second person (the RP-2) during the overlap. Similarly, there was a TUL-1 and a TUL-2 for planning any particular sol, etc.

RSVP: The Rover Sequencing and Visualization Program, the software suite I helped write for MER. It's the software we use to drive (and, more generally, to command) the rovers.

SAP: Science Activity Planner, a sort of software whiteboard we use to sketch out our high-level plan for the day before we get down to the real low-level work of sequencing it all. A.k.a. "Maestro."

SEU: Single-Event Upset. Generally, it means a cosmic ray flipped a bit in the computer's memory.

SMSA: Surface Mission Support Area. It's the nerve center of the surface mission, the room you saw on TV. Downlink and uplink happen there, though sequencing -- putting together the commands for the rover, the stuff I did for most of my day -- happens in another room, the Sequencing MSA (which, confusingly, has the same initials).

SOWG: Science Operations Working Group, the name of the meeting where they formally sketch out the high-level science goals for the day. Typically pronounced "sog," as if there were no "w."

SSTB: Surface System Testbed. This is usually a shorthand for the SSTB rover, our Earth-bound pseudo-copy of Spirit and Opportunity that we drive around in our testbed. There's also the SSTB-Lite rover, which is missing an arm and a camera mast but is still useful for testing mobility.

Stutter-step: We don't have cameras showing the underside of the rover, and in particular part of the volume through which we deploy the arm is invisible. So at the end of a drive, we often take what we call a "stutter-step": take a HAZCAM image, drive forward a little, and then take another HAZCAM image. The first image shows us what's under the rover at its final position, and of course the second image shows us what's in front of us at the very end.

TAP/SIE: Tactical Activity Planner / Sequence Integration Engineer. This started out as two separate positions in the nominal mission. (I was originally offered an SIE job, incidentally.) The TAP was responsible for capturing and refining the science team's high-level plan for the sol, and the SIE was responsible for building the skeleton structure of sequences for the rover for the day, ensuring that all of the sequences built by the rover drivers, the science team, and others would all be invoked at the right times. Once we moved into the extended mission, a lot of this work was automated and the two positions were merged into one.

Terrain mesh: The 3-D model of the world around the rover, built from stitched-together pairs of images we downlink each sol.

TDL: Tactical Downlink Lead, the person in charge of a given sol's downlink analysis.

TPS: Thermal Protection Subsystem -- the heat shield and supporting components. This was built at Lockheed Martin Aerospace in cooperation with JPL engineers (who are not usually part of the MER ops team).

TUL: Tactical Uplink Lead, the person in charge of a given sol's uplink process.

Visodom: Short for "visual odometry," visodom is a technique for correcting the rover's idea of her position. The rover takes a picture (really, a pair of pictures, usually with the NAVCAMs), moves a little way -- usually not more than 60cm -- and takes another picture-pair. She then builds a 3-D map from each picture-pair and works out how objects appear to have moved between the two images; from that, the rover can figure out how she actually moved. If, say, she's climbing a hill, she might be slipping in the soil so that instead of moving 60cm, she moved only 40cm. She'll update her position estimate accordingly, and move on. Among other things, visodom helps us reliably follow a path in terrain where the rover's own motion is hard to predict.

WEB: Warm Electronics Box, the gold box that forms the main body of the rover.

Dramatis Personae

Ali, Khaled: Khaled worked on MER flight software development, and started ops working in data management. He started training as a rover driver about a year into the surface mission.

Arvidson, Ray: MER's Deputy Principal Investigator -- the number-two science guy, under Squyres. Ray's a veteran of Mars missions going back to Viking and led the science team for Spirit for most of the mission.

Biesiadecki, Jeff: MER flight software developer and fellow rover driver. Jeff wrote the rovers' low-level mobility and motor-control code. Plus, he was the person who recommended me to Cooper in the first place; without Jeff's recommendation, I'd probably never have worked on MER at all. He's married to Cindy Oda.

Callas, John: John was Jim Erickson's Deputy Project Manager when Jim was the Project Manager. When Jim moved on to MRO, John became the Project Manager, a role he retains to this day.

Cooper, Brian: Fellow RSVP developer and rover driver. Cooper was the RSVP development lead and the rover driver team lead (until he moved on and I took over the latter role a couple of years in).

Eelkema, Emily: Not to be confused with "PANCAM Emily" (Emily Dean), Emily Eelkema was a TUL during the nominal mission and well into the extended mission, before leaving to work on MSL and, currently, Cassini.

Elachi, Charles: JPL Director. If JPL were a company, he'd be the CEO.

Erickson, Jim: His series of leadership roles in the project took Jim up to the Deputy Project Manager and then Project Manager positions before he left to become Project Manager for the Mars Reconnaissance Orbiter.

Ghandchi, Saina: After cruise ops, Saina became a TDL; she was later a TUL.

Hartman, Frank: Fellow RSVP developer and rover driver.

Laubach, Sharon: Like her husband, Andy Mishkin, an indispensable genius. She co-developed (with Andy) the surface ops process and (with Marc Pack) many of the scripts we now use to automate broad swaths of that process, among lots of other things. She started surface ops as a TAP/SIE and is currently the IST team chief, putting her in charge of about half of MER's engineering team. She is probably the smartest person I actually know.

Mishkin, Andy: A TUL and IST team chief during the nominal mission, Andy also designed the MER surface operations process (with Sharon Laubach) -- both the original version, and a couple of revised versions that adapted to MER's extended mission requirements. He's one of your basic all-around indispensable genuises.

Oda, Cindy: Cindy wrote part of MER's flight software -- the telecom code, I think -- then became a TAP/SIE, then a TUL, and finally a Mission Manager before reluctantly jumping ship for MSL. She is one of the very nicest people I have ever met. She's married to Jeff Biesiadecki.

Squyres, Steve: Oh, come on, you know who Steve is.

Theisinger, Pete: MER Project Manager, from the beginning of development all the way through the nominal mission.

Townsend, Julie: Julie was involved in MER pretty much from its inception -- MER was her first job out of college, if you can imagine that. An all-around brilliant engineer, she worked on MER's development and cruise phase, and in surface ops she was a TUL. She's now a rover driver.

Trebi-Ollennu, Ashitey: At the beginning of our story, a Mobility/IDD team member, responsible for monitoring the health and safety of the rover's wheels and arm. Later a rover driver, before he abandoned us like a big quitter ;-) and went over to work on Phoenix.

Wright, John: Fellow RSVP developer and rover driver.

Yen, Jeng: Fellow RSVP developer and, at the beginning of our story, a Mobility/IDD team member, responsible for monitoring the health and safety of the rover's wheels and arm. Later (and currently) a rover driver.

2 comments:

I suppose I've been a little slack about making sure everyone who's frequently referenced is included in the list of Dramatis Personae. I've tried to correct that; let me know if I've overlooked anyone.